Lubricant



Patented Nov. 1 6, 1926.

UNITED STATES PATENT OFFICE.

EDWARD M. HONAN, OF EAST ORANGE, NEW JERSEY, AND JOHN B. TOWNSEND, OF

BROOKLYN, NEW YORK, ASSIGNORS TO WESTERN ELECTRIC COMPANY, INCOR- PORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

LUBRICANT.

No Drawm g.

This invention relates to lubricant compositions and has particular application to ubricants for use in electrical apparatus.

It is an object of the invention to provide a solid lubricant adapted for lubricating electrical apparatus. I

Another object is the provision of a vehicle for applying a uniform film of lubricant over a surface.

Customary practice in solving problems of lubrication, comprises the use of an oil having as'low a viscosity as is consistent with the maintenance of a film between the wearing parts, low viscosity oils usually being chosen, as such oils generally possess a low surface tension.

In the lubrication of electrical apparatus, however, the use of a liquid lubricant is often not desirable, as such lubricants usually hold dust and may cause trouble by carrying dust to sensitive parts of the apparatus. Nondust collecting lubricants, are, therefore, de-' sirable for use as lubricants for electrical ap paratus.

A feature of the invention is the provision of a solid lubricant which is non-dust collecting and non-conducting and which is suitable for application to electrical apparatus.

In accordance with the features of the invention, there is provided a lubricant comprising a mixture of spermaceti wax and petrolatum, composed principally of spermaceti wax, dissolved in carbon tetrachloride as a vehicle. It has been found that lubricants comprising s ermaceti wax and petrolatum and compose principally of spermaceti wax will not appreciably corrode or gum after long exposure to surface conditions, will substantially reduce friction or wear of the rubbingparts and when roperly proportioned will satisfactorily a ere to the wear-. ing surface, willbe non-dust collecting and ma be easil satisfactory ubricants for such pieces of electrical apparatus as the brushes and bank terminals of selectorv switches, for example.

As a solvent vehicle with the lubricant of this invention, carbon tetrachloride has been found to be particularly satisfactory, as it possesses a hi h evaporation rate, eliminates the fire hazar s usually present when a vola-- tile vehicle is employed, and readily disapplied, sothat they make.

v Application filed December 17, 1924. Serial No. 758,556.

solves mixtures of spermaceti wax and petrolatum.

The proportions of spermaceti wax and petrolatum which may be employed to form satisfactory lubricants may be considerably varied, changes in such roportions varying the adherence, dust-col ecting ability, and the. actual lubrication value of the particular lubricant formed. It has been found that, as a general rule, the higher the spermaceti wax content, the less appears to be the dustcollecting ability of the lubricant. While less dust appears'to be collected with higher contents of spermaceti wax, however, it has been further noted that the lubricant shows a tendency towards becoming non-adherent and less unguentous with high contents of spermaceti wax.

The preferred proportions are 50% to 90% spermaceti wax and'the remainder petrolatum, but it will be appreciated that it is not intended to impose any restrictions upon the, proportions of the ingredients employed other than those'set forth in the claims.

It is convenient to melt the petrolatum with gentle heat to such a temperature that the spermaceti will slowly dissolve atit is stirred in small uantities ata-time; It is very important't at neither' 'the spermaceti nor the petrolatum shall be allowed to become hot enough to change color, or to give off the easily recognizable overcooked smell, due to chemical changes which occur if heated much beyond the point necessary for the thorough liquefying and mixing of the spermaceti and petrolatum.

I next remove the vessel in which the above melting has been performed and slowly pour the melted mixture into a large vessel oftetrachlori'de of carbon, stirring the same so that no undissolved chilled material accumulates on the bottom. When the whole of the mixture has been poured in the tetrachloride, a slightly turbid but limpid and,

uniform solution results, which on standing warmed suificiently to soften it, is stirred into the melted petrolatum, the heating of which is increased slowly until-the spermaceti dissolves off of the spoon as it is stirred, the wax is then worked in a spoonful at a time until the whole pounds has been dissolved and the solution is then immediately taken off of the heater and may be allowed to stand a few minutes if desired to cool and to settle any sediment which may be in the wax and petrolatun'l. It is then poured slowly while stirring into gallons of carbon tetrachloride.

The proportions of carbon tetrachloride employed to form the lubricant solution will depend upon the particular use to which the lubricant is to be applied. It is, of course, obvious that it is always desirable to have the carbon tetrachloride content as low as possible so that a rapid evaporation rate will result. The amount of carbon tetrachloride employed, therefore, will depend upon the restrictions placed upon the viscosity of the lubricant, as applied. A solution of spermaceti wax and petrolatum in carbon tetrachloride and containing 5% by Weight of the lubricant mixture has been found to be satisfactory for use when the lubricant is to be sprayed upon the wearing parts.

Another characteristic of the lubricants of this invention is that they possess low contact resistances with small current values. The advantage of this feature is that any small amount of this lubricant which may reach an electrical conducting surface during application will not appreciabl affect the operation of the apparatus to w ich the lubricant is applied. It has been found, for example,

that in lubricating selector switch brush contacts, any of the lubricant which may be applied to the selector brushes does not appreciably affect the transfer of low currents across the contacts. 1

The lilbricants of this invention may be applied in any desired manner such as by application with a brush or by spraying, for example.

Though illustrated by its application generally to electrical apparatus and specifically to selector switches, it is evident that the invention is not limited to these applications alone, but is susceptible of various changes and adaptations within the scope of the ap- EDWARD M. HONAN. JOHN R. TOWNSEND. 

